# Reversing an equation

• Jan 16th 2008, 05:39 PM
victurbo
Reversing an equation

Need to figure out how to reverse this equation for work...

C = 4.42 - .113 * A + 0.0406 * B

C = Dwell time in a vessel in minutes

A = Screw speed drawing material out of a vessel in RPM's

B = Level in the tank in inches

How do I solve for "B" if I know what cook time I want to target?

Thanks for any assistance in advance. My brain must be broken as this seemed simple until I actually sat down and tried to figure it out.
• Jan 16th 2008, 06:02 PM
mr fantastic
Quote:

Originally Posted by victurbo

Need to figure out how to reverse this equation for work...

C = 4.42 - .113 * A + 0.0406 * B

C = Dwell time in a vessel in minutes

A = Screw speed drawing material out of a vessel in RPM's

B = Level in the tank in inches

How do I solve for "B" if I know what cook time I want to target?

Thanks for any assistance in advance. My brain must be broken as this seemed simple until I actually sat down and tried to figure it out.

What do you mean by "cook time"?
• Jan 16th 2008, 07:16 PM
victurbo
Cook Time = Dwell Time

Sorry for the confusion. It's the order of transposition I'm struggling with. Algebra was a long time ago.
• Jan 16th 2008, 08:52 PM
mr fantastic
Quote:

Originally Posted by victurbo
Cook Time = Dwell Time

Sorry for the confusion. It's the order of transposition I'm struggling with. Algebra was a long time ago.

Quote:

Originally Posted by victurbo

Need to figure out how to reverse this equation for work...

C = 4.42 - .113 * A + 0.0406 * B

C = Dwell time in a vessel in minutes

A = Screw speed drawing material out of a vessel in RPM's

B = Level in the tank in inches

How do I solve for "B" if I know what cook time I want to target? [snip]

C = 4.42 - .113 * A + 0.0406 * B

therefore C - 4.42 = - .113 * A + 0.0406 * B

therefore C - 4.42 + .113 * A = 0.0406 * B

therefore (C - 4.42 + .113 * A)/0.0406 = B.

B = (C - 4.42 + .113 * A)/0.04

Of course, you won't be able to get a value for B unless you also know the value of A .....
• Jan 17th 2008, 06:11 AM
victurbo
That did it
Thanks for the help.